1. Field of Invention
The present invention relates to a charge pump circuit. More particularly, the present invention relates to a charge pump circuit generating a voltage which is a multiple of the original signal.
2. Description of Related Art
Charge pump circuits are a type of DC-DC converter which uses capacitors as energy storage device and are able to provide a power source at a higher or lower voltage than that obtained from an input source. Charge pump circuits are capable of high efficiencies, sometimes as high as 90-95%. Charge pumps, employing some switching devices to control the connection between the capacitors and the voltage sources, typically obtain voltages greater than the original input voltage. To increase the voltage, this kind of charge pump includes one capacitor for storing and transferring charge to other capacitors.
The switch devices, controlling the connection between the capacitors, are driven by a driving pulse signal which is generated by a charge pump driving circuit. However, the transistors of the charge pump driving circuit usually suffer from short circuit flowing from the supply terminal to the ground terminal when the transistor are switching, which consumes much power.
Therefore, there is a need for a new charge pump driving circuit which can reduce the short circuit current and thus reduce the power consumption.